OK, what I did was I tried a bunch of tests and also went to
The Johnson O'Connor Research Institute to see what they said. For me, all the results from the various tests pointed to the same kind of jobs. None of which I'm in now

.
The one site I really liked was
DiscoverYourPersonality.Com. There they had the Myers-Briggs, which is the standard personality/career test tool used by most companies and The Strong Career Test.
CareerPlanner.com wasn't as in-depth but it backed the results from the Myers-Briggs and the Strong and JOC. I wasn't too fond of
MyAnsir as it seemed to give more generalized, less complete answers. What was interesting was the Kiersey Temperment Sorter at
AdvisorTeam. It seemed to complement what everything else did.
What I did then was use
The Oxford Program to see how well the career matches from the previous personality tests matched a testing tool geared primarily for career suitability/temperment. Again, the results were complementary.
It appears I'm easy to pigeonhole.
While all this might sound dull it was actually quite reassuring to see that so many different tests and inventorys matched within the same general area. When I go back to school I can be reasonably assured that I won't be getting a degree in something I absolutely hate with jobs I will hate. Sometimes the ideal and the reality of a career are completely different. I don't want to go down that path. Been there, done that.
All of these were good sites that delivered what they promised and gave me what I asked for. They weren't cheap but I figure spending the money is an investment in my future. Johnson O'Connor was really the best. Having someone who counsels you is a tremendous advantage because you can address any concerns you might have right there and then.
I hope this helps. You're not alone in any of this and if it's any consolation the Department of Labor figures that the average American these days will have 3 different careers in a lifetime. We're living in a brave new world, might as well try to enjoy the pioneering experience in career transience.
Oh and btw, I'm an INTP/INFP. This bizarre archetype I've dubbed, "The Saintly Critic".